Refer to figure.

The total mass of the helicopter can be said to act through one point called Centre of Gravity (CG).

If the extended line of the Total Rotor Thrust (TRT) is ahead of the centre of gravity (CG), it means that that the helicopter has an aft CG.

1. An aft CG will result in a nose pitch-up fuselage attitude, reduce drag, the stabiliser will be less loaded, thus the range, endurance and rate of climb capability will increase, and its specific fuel consumption will decrease.

If the CG is too far aft close to the aft limit, there may be insufficient forward cyclic to prevent the tail rotor and boom from striking the ground.

Also, the amount of forward cyclic control available will be further reduced, because some available cyclic movement will already have been used to overcome the tail down moment and the helicopter will be longitudinally less stable.

2. A forward CG, in front of the TRT, results in a nose pitch-down fuselage attitude, increasing its drag and horizotal stabiliser's aerodynamic load, producing an even greater downforce.

To compensate for the nose-down attitude, aft cyclic is required to maintain a level attitude, thus, the cyclic control range availability backwards is reduced.

If the CG is too far forward close to forward limit, there may be insufficient aft cyclic to hold the helicopter in a given position, particularly in the hover. It may be unable to flare, thereby increasing the landing distance and it may be impossible to achieve a level-skid landing, causing damage to the skids.

Among the costs mentioned above because of a forward CG, the only positive outcome is that the helicopter will be longitudinally more stable.